Devices for dispensing two or more biocomponents are known. In the medical device field, such devices are typically used for applying bioadhesives, polymers and other synthetic material used in wound closure. Because of the reactant nature of certain biocomponents used to form a bioadhesive, mixing of the components does not occur until immediately before the mixture is ready to be applied. Mixing of the components too soon before application may result in premature hardening of the mixture, thereby making application of the solution impossible. Thus, in these devices, the two or more components are maintained separately until just prior to application. While quick reaction of the components to form a sealant is quite good for its purpose, this characteristic poses challenges for delivery devices due to a high risk of clogging. For example, fibrin sealant delivery device dispensing tips can easily become non-functional due to clogging. To help address this challenge, typical delivery devices do not mix fibrin sealant components until they are just proximal to the dispensing end of the device. However, clogging remains a problem even with this approach due to residual components in the device after delivery.
Clogging is particularly a problem when there is intermittent use of a delivery device. Intermittent use may be required during a procedure for a variety of reasons, and the repeated starting and stopping of delivery often tends to clog the outlet of the applicator tip. As a result, most applicator assemblies are provided with a number of replacement tips for when clogging of the tip occurs. However, replacing clogged applicator tips interrupts the flow of a procedure, is time consuming and is an added expense. Previous methods and devices have incorporated features such as a flexible diaphragm or flexible flap tip, for example.
There is a need for an easy and reliable way to reduce clogging in a dispenser tip when not in use, even when rapidly-reacting materials are to be dispensed.